Electrical collector ring assembly



Mmhv 9, i954 P. w. NIPPERT ELECTRICAL COLLECTOR RING ASSEMBLY Filed April 17, 1951 Patented Mar. 9, 1954 UNITED STATES PATENT OFFICE ELECTRICAL COLLECTOR RING ASSEMBLY Application April 17, 1951, Serial No. 221,385

3 Claims. l

rlhe present invention relates to collector ring assemblies for motors and generators. More specifically, the invention comprises an assembly including an insulating sleeve which carries, concentrically, a plurality of longitudinally arranged electrical conductor rings, spaced from one another by one or more insulating rings. The electrical collector rings are crimped into the sleeve by crowding the material of the rings, adjacent the sleeve, in a radial inward direction.

In the manufacture of such collector ring assembly, the collector rings are pressed longitudinally over the insulating sleeve. In so doing, part of the metal of the collector ring is rubbed oif of the ring and deposited on the insulating sleeve. To prevent the short circuiting or the conducting of current through the metal depos ited on the sleeve from one ring to another, a peripheral recess is formed in the sleeve in the area preferably intermediate the ultimate position of theA conductor rings. Such recess is not necessary when two collector rings only are employed and when the method of assembling the rings upon the sleeve is carried out in accordance with the method herein described. Such recess power is desirable when more than two collector rings are assembled on the sleeve.

Other and furthei` objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein preferred forms of embodiments of the invention are clearly shown.

Referring to the drawings:

Fig. 1 is a View partly in section showing the improved assembly.

Fig. 2 is an exploded view of the assembly shown in Fig. 1.

Fig. 3 is a sectional view of a fixture employed in the method of assembling the rings on the sleeve, and a sectional View of one of the rings in set position and a sectional view of another ring about to be pressed into position.

Fig. 4 is a view at right angle to that shown in Fig. 3 but showing the second ring pressed in its set position.

Fig. 5 is a sectional view taken on line 5-5 of Fig. 1; and

Fig. 6 is an elevational view, partly in section, showing a modifying form of assembly wherein the assembly will include three collector rings.

Referring first in detail to the collector ring assembly shown in Fig. l, the insulating sleeve is shown at 2 I. This sleeve is stable and is preferably formed of glass bers and suitable binding (Cl. S10-232) material, formed of a suitable thermal setting plastic. If desirable this insulating sleeve may be reenforced by a metallic bushing or sleeve 22 in the forni of a sleeve. Such bushing may include a flare 23 at one end. Preferably, the outer surface of sleeve 22 is provided with a series of knurls 2d, which, in the preferred form, extend longitudinally of the sleeve. In this embodiment two rings 25 and 2t are arranged concentricaily on the sleeve and spaced longitudinally from one another and insulated from one another preferably by a plurality of insulating rings 2i. Each of the series of knurls 24 stop short of opposite surfaces of the rings 25 and 26, approximately .G15 of an inch i. e. the knurls are approximately .030 inch shorter than the width of a ring 25 or 2E. The inside diameter of sleeve 2| is slightly less than the outside diameter of sleeve 22 and the sleeve 2| is telescopically pressed onto sleeve 22. Thereafter the outside cylindrical surface of sleeve 2| is machined to the desired size.

The top and bottom sections 0f the ring 25 are circumferentially crimped into the peripheral surface of the insulating sleeve 2| i. e. the top and bottom surfaces of ring 25 are crowded radially inwardly as shown in somewhat exaggerated proportion at 29 and 3E. The top section of ring 26 is likewise crimped and thereby crowded into the peripheral surface of the sleeve 2l. The latter crimp is shown at 3|.

An electrical conductor in the form of an insulated wire is connected in any suitable manner to each of the rings. In the preferred form, the conductor ring is provided with a bore 33 to receive the insulated wire 34 and. is also drilled, eoncentrically with the bore 33 to receive the bared portion 35 of the wire 34. After the wire is in position the metal about a part of the bared portion 35 is crimped radially outwardly so as to bind the bared portion 35 in intimate metallic and in stable relation with the ring. The lower ring 25 is also provided with a bore 31 equal in diameter, throughout the width of the ring 25,v to that of the bore 33 for receiving the wire 38 which is connected with the ring 26 in the same manner that the wire 34 is connected withr the rings 25.

A xture 39 is employed in the manufacture of the assembly. rilhis fxture is recessed as indicated at 4D, the recess having an external diameter substantially the same as the external diameter of the sleeve 2|. The xture 39 is also provided with a relatively larger recess 4| for receiving the ring 25. Preferably the ring 25 is first placed within the recess 4| of fixture 39 and then the sleeve 2| or the composite assembly of the sleeve 2| and the reenforcing sleeve 22 are forced into the ring 25 until the sleeve or sleeves bottom on the bottom of recess 40. A slot 43 is formed in the side of the fixture 39 for receiving the wire 34. After the sleeve 2| or sleeves 2| and sleeve 22 are pressed into position, a cylindrical crimping tool 44 is brought into engagement with the top surface of ring 25. The internal diameter of the crimping tool 44 is substantially the same as the external diameter of the sleeve 2 The extreme bottom of the crimping tool 44 is provided with a plurality of downwardly extending V-shaped projections 45. These V-shaped projections are circumferentially arranged so that when the projections 45 are pressed against the top section of the ring 25, the metal of the top section of the ring 25 will be crimped inwardly radially into the sleeve 2| i. e. the metal lying inwardly of the projections 45 will be crowded into firm gripping relationship with the sleeves 2 The crowding of the metal will force the material of sleeve 2| into the holes of the knurled section of the sleeve 22 to cause the sleeve 2| to more firmly grip the other surface of sleeve 22.

The insulating rings 21 are then placed on top of the ring 25.

'l'he next operation is to place the ring 23 in position and this is accomplished by threading the wire 38, which is attached to ring 29, through the bore 33 of ring 25. A slot 41 is formed in the fixture 39 for the reception of the wire 38. Pressure is then applied to the top surface of ring 26 to press the ring about the sleeve 2|. A separate tool may be used for this purpose, or the crimping tool 44 can be used. After the bottom of ring 25 is pressed firmly upon the top ring 21, to compress the rings 21, the circumferentially arranged projections 45 will bite into the top section of the ring 26 to crimp the ring 26 against the sleeve in the same manner as explained with respect to the crimping of ring 26 with the sleeve 2|.

The assembly is then removed from the fixture 39 and turns upside down so that ring 2B is bottomed in the recess 4I. Pressure is then applied between the crimping tool 44 and the assembly so as to crimp the then top section of the ring to the sleeve 2| i. e. the crimp 29 is formed.

. Although a crimp in the form of an unbroken circle provides adequate grip between a ring and the sleeve, I have found that the gripping can be enhanced by forming the crimping tool with a plurality of crimping projections or sectors. I have found that greater radial inward distortion of the metal takes place at the ends of the sectors than that which takes place intermediate the ends. Obviously, also the projection or projections must have a gap so as to span the wire 38.

In Fig. 6, which shows a sleeve |2| for what will ultimately be a three ring assembly, is provided with an annular recess 50. The rings 25 and 26 are assembled onto the sleeve |2| in the same manner as disclosed with respect to the embodiment heretofore described. When the ring 23 is placed into position, the periphery of the sleeve |2| has an abrasive effect upon the metal of the inter periphery of ring 26. This metal will be rubbed off onto the sleeve |2I. By providing the annular recess 50, deposition of metal around the periphery of the sleeve |2|, directly above the ring 26, is prevented and therefore, the ring thereabove will be completely insulated from the ring 26.

From the foregoing it will be understood that I have provided a collector ring assembly which not only is sturdy in construction but also can be manufactured at a relatively low cost.

While the forms of embodiments of the present invention as herein disclosed constitute preferred forms, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow:

I claim:

1. A collector ring assembly comprising, in combination, a cylindrical core an insulating sleeve on the core; a plurality of spaced electrical conductor rings on the sleeve; and an insulating ring on the sleeve between the rings, said conductor rings being crimped into the sleeve by flowing material of the conductor rings, adjacent the sleeve, radially inwardly.

2. A collector ring assembly comprising, in combination, a core having knurls formed in the outer surface thereof; an insulating sleeve on the core; a plurality of spaced electrical conductor rings on the sleeve; and an insulating ring on the sleeve between the rings, said conductor rings each being crimped into the sleeve by flowing material of the ring, adjacent the sleeve, radially inwardly.

3. A collector ring assembly comprising, in combination, a core having longitudinally extending knurls formed in the outer surface thereoi'; with the knurls being grouped in circumferentially extending bands successively spaced in the direction of the axis of the core; an insulating sleeve on the core; a plurality of spaced electrical conductor rings on the sleeve with said rings being successively aligned over the bands of knurls; and an insulating ring on the sleeve between the rings, said conductor rings each being crimped into the sleeve by flowing material of the ring, adjacent the sleeve, radially inwardly.

PAUL W. NIPPERT.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 659,443 Gill Oct. 9, 1900 1,416,243 Thomas May 16, 1922 1,870,236 Chervenka Aug. 9, 1932 2,025,223 Watson Dec. 24, 1935 2,126,452 Creveling Aug. 9, 1938 2,385,792 Carlson Oct. 2, 1945 

